scholarly journals Seven Decades of Spontaneous Forest Regeneration after Large-Scale Clear-Cutting in Białowieża Forest do not Ensure the Complete Recovery of Collembolan Assemblages

Forests ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 948
Author(s):  
Marek Sławski ◽  
Małgorzata Sławska
Keyword(s):  
Large Scale ◽  
Life Form ◽  
Group Structure ◽  
Complete Recovery ◽  
Long Term Effects ◽  
Old Growth ◽  
Soil Microarthropods ◽  
Clear Cutting ◽  
Białowieża Forest ◽  
Large Scale Disturbance

The long-term effects of large-scale disturbance on forest ecosystem processes and structure are poorly understood. To assess the effects of large-scale clear-cutting on the taxonomic and functional structure of collembolan assemblages, 18 plots were established in the Polish part of Białowieża Forest. All plots, situated in a mixed Tilio-Carpinetum broad-leaved forest, had eutrophic Cambisol developed on rich glacial deposits. The Collembola assemblages in the stands that had naturally regenerated on large-scale clear-cuts performed at the beginning of the 20th century were compared to those in old-growth forests (i.e., the endpoint of stand development following stand-replacing disturbance). Collembolans, one of the most numerous soil microarthropods, are successfully used to assess the consequences of forest management and ecosystem restoration. Our study tested whether seven decades of spontaneous forest development after large-scale anthropogenic disturbance ensures the complete recovery of the soil Collembola. Using complementary taxonomic and life-form approaches, we provide evidence that the collembolan assemblages associated with the tree stands that had spontaneously developed in large harvesting plots distinctly differed from those in old-growth deciduous forests in this region despite seven decades of regenerative forest succession. The species diversity of the assemblages in the naturally regenerated tree stands was significantly lower, and their life-form structure was noticeably different from those in the reference forests. Moreover, the shift in the functional group structure of the collembolan assemblages in the stands that had regenerated after clear-cutting indicates that their activity seven decades after disturbance is concentrated mainly on the decomposition of the litter in the upper layers, whereas the processes controlled by these organisms in the deeper soil layers are not fully restored.

Effects of experimental harvesting on spider (Araneae) assemblages in boreal deciduous forests

2008 ◽  
Vol 140 (4) ◽  
pp. 437-452 ◽  
Author(s):  
Christopher M. Buddle ◽  
David P. Shorthouse
Keyword(s):  
Indicator Species ◽  
Boreal Forests ◽  
Large Scale ◽  
Wolf Spider ◽  
Natural Disturbance ◽  
Old Growth ◽  
Partial Cutting ◽  
Clear Cutting ◽  
Old Growth Forests ◽  
Geographic Separation

AbstractTwo large-scale forestry experiments, in Quebec (Sylviculture et aménagement forestiers écosystémique (SAFE)) and Alberta (Ecosystem Management by Emulating Natural Disturbance (EMEND)), were established in the late 1990s to test the effects of alternative silvicultural strategies (e.g., partial cutting) on biodiversity in northern boreal forests. We collected spiders in pitfall traps 2 years after the application of partial-cutting treatments in deciduous stands at EMEND and 6 years after similar treatments in deciduous stands at SAFE. Although we are aware of the challenges imposed by disparate locations and whole-scale experimental methods, our objective was to compare the effects of partial cutting on spider assemblages (diversity and community composition), and in doing so, to formulate a few general statements. Overall, 98 species (6107 individuals) were collected from Alberta and 86 species (3414 individuals) from Quebec. Of these, 44 species were common to both regions. Ordination and indicator-species analyses revealed a distinct effect of geographic separation: the spider assemblages in deciduous stands within the boreal plains ecoregion of Alberta and the boreal shield in Quebec were distinct. However, the effects of partial cutting on spider assemblages within each project were similar: removal of 25%–33% of trees shifted a characteristic old-growth fauna toward one more typical of clearcuts. Indicator-species analysis also revealed the dominance of wolf spider (Lycosidae) species in clearcuts within both experiments and we present evidence that clear-cutting homogenizes spider assemblages. Old-growth forests contain spider faunas that are easily disrupted by moderate partial cutting. In the face of intense harvesting practices, managing for the maintenance of biodiversity and conservation of spider faunas in northern forests will require retention of old-growth forests.

scholarly journals Predicting the potential for old-growth forests by spatial simulation of landscape ageing patterns

2003 ◽  
Vol 79 (3) ◽  
pp. 621-631 ◽  
Author(s):  
Ajith H Perera ◽  
David J.B. Baldwin ◽  
Dennis G Yemshanov ◽  
Frank Schnekenburger ◽  
Kevin Weaver ◽  
...  
Keyword(s):  
Temporal Variation ◽  
Large Scale ◽  
Simulation Modelling ◽  
Spatial Simulation ◽  
Old Growth ◽  
Disturbance Regimes ◽  
Old Growth Forest ◽  
Large Scale Disturbance ◽  
Old Growth Forests ◽  
Spatio Temporal

Planning for old-growth forests requires answers to two large-scale questions: How much old-growth forest should exist? And where can they be sustained in a landscape? Stand-level knowledge of old-growth physiognomy and dynamics are not sufficient to answer these questions. We assert that large-scale disturbance regimes may provide a strong foundation to understand the spatio-temporal ageing patterns in forest landscapes that determine the potential for old growth. Approaches to describe large-scale disturbance regimes range from scenarios reconstructed from historical evidence to simulation of landscapes using predictive models. In this paper, we describe a simulation modelling approach to determine landscape-ageing patterns, and thereby the landscape potential of old-growth forests. A spatially explicit stochastic simulation model of landscape fire–forest cover dynamics was applied to a 1.8 million-ha case study boreal forest landscape to quantify the spatio-temporal variation of landscape ageing. Twenty-five replicates of 200-year simulation runs of the fire disturbance regime, at a 1-ha resolution, generated a suite of variables of landscape ageing and their error estimates. These included temporal variation of older age cohorts over 200 years, survivorship distribution at the 200th year, and spatial tendencies of ageing. This information, in combination with spatial tendency of species occurrence, constitutes the contextual framework to plan how much old-growth forest a given landscape can sustain, and where such forest could be located. Key words: landscape management, old growth, spatial simulation modelling, landscape ecology, boreal forest, Ontario, fire regime simulation, natural forest disturbances, stochastic models, age-class distribution

scholarly journals Hypogeous Fungi Occurrence, Distribution and Mycorrhizal Hosts in Grand Teton National Park and John D. Rockefeller, Jr. Memorial Parkway

1989 ◽  
Vol 13 ◽  
pp. 111-122
Author(s):  
Steven Miller ◽  
Nancy Stanton ◽  
Stephen Williams
Keyword(s):  
Mycorrhizal Fungi ◽  
National Park ◽  
Large Scale ◽  
Forest Ecosystems ◽  
Coniferous Forest ◽  
Root Systems ◽  
Hypogeous Fungi ◽  
Clear Cutting ◽  
Large Scale Disturbance ◽  
Insect Attack

The persistence of mycorrhizal fungi in undisturbed coniferous forest ecosystems is assumed by the renewed appearance of their sporocarps each year. Sporocarps, however, are not produced in areas severely disturbed by fire or clearcutting; yet spores and other propagules of some species of hypogeous fungi are present in the soil in the absence of suitable mycorrhizal hosts, and are capable of forming mycorrhizae several years after clear-cutting or fire (Miller et al. 1989). In fact, hypogeous fungi such as Rhizopogon spp. are typically the first to recolonize root systems of new seedlings after large scale disturbance such as fire, insect attack, or clearcutting (Miller et al. 1989). Are these fungi residual in the soil from previously existing spore banks, or are they continuously being restocked into the area? Information on strategies for persistence, propagation and survival of ectomycorrhizal fungi is required before responses of forest ecosystems to fire and other disturbance can be understood.

The relationship of the soil seed bank and understory vegetation in old-growth northern hardwood–hemlock treefall gaps

1990 ◽  
Vol 68 (12) ◽  
pp. 2714-2721 ◽  
Author(s):  
David J. Mladenoff
Keyword(s):  
Seed Bank ◽  
Large Scale ◽  
Soil Seed Bank ◽  
Forest Understory ◽  
Betula Alleghaniensis ◽  
Forest Change ◽  
Old Growth ◽  
Northern Hardwood ◽  
Treefall Gaps ◽  
Large Scale Disturbance

In mature northern hardwood forests, small treefall gaps constitute an important mode of compositional and structural change within the long return time of larger catastrophic disturbances. The soil seed bank and patterns in vegetation layers are described in this disturbance regime context. In these small treefall gaps, herbaceous and woody vegetation species present are similar to those of forest understory plots, differing primarily in abundance. Seed bank communities are compositionally more similar among gaps than forest understory plots, but vegetation similarity is equal among forest plots and among gaps. Seed bank-vegetation similarity is greater among forest plots than in gaps. Seed bank strategies differ among the plant species characteristic of the differing forest layers. Dominant canopy tree species (Acer saccharum, Tsuga canadensis, Betula alleghaniensis) are not an important component of the seed bank. Bird-dispersed shrub and herbaceous species and ant-dispersed herbs are important in the seed bank, especially in gaps. In particular, based on gap seed bank response, it appears that understory shrub abundance and pattern within the forest change with the time since large-scale disturbance, in accordance with species adaptations to the size and increase in number of small treefalls in the mature forest. These species patterns may relate to the patchy nature of resource availability that develops, especially that of nitrogen, which is controlled by the canopy species–gap mosaic. Key words: treefall gaps, soil seed bank, disturbance, northern hardwoods, old growth, succession, shrubs.

Experiences With and Lessons Learned From Developing, Implementing, and Evaluating a Support Program for Older Hearing Aid Users and Their Communication Partners in the Hearing Aid Dispensing Setting

2020 ◽  
Vol 29 (3S) ◽  
pp. 638-647 ◽  
Author(s):  
Janine F. J. Meijerink ◽  
Marieke Pronk ◽  
Sophia E. Kramer
Keyword(s):  
Large Scale ◽  
Hearing Aid ◽  
Critical Discussion ◽  
Lessons Learned ◽  
Research Note ◽  
Support Program ◽  
Large Sample Size ◽  
Long Term Effects ◽  
Communication Program ◽  
Communication Partners

Purpose The SUpport PRogram (SUPR) study was carried out in the context of a private academic partnership and is the first study to evaluate the long-term effects of a communication program (SUPR) for older hearing aid users and their communication partners on a large scale in a hearing aid dispensing setting. The purpose of this research note is to reflect on the lessons that we learned during the different development, implementation, and evaluation phases of the SUPR project. Procedure This research note describes the procedures that were followed during the different phases of the SUPR project and provides a critical discussion to describe the strengths and weaknesses of the approach taken. Conclusion This research note might provide researchers and intervention developers with useful insights as to how aural rehabilitation interventions, such as the SUPR, can be developed by incorporating the needs of the different stakeholders, evaluated by using a robust research design (including a large sample size and a longer term follow-up assessment), and implemented widely by collaborating with a private partner (hearing aid dispensing practice chain).

scholarly journals Process Simulation and Techno-Economic Analysis of Large-Scale Bioproduction of Sweet Protein Thaumatin II

Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 838
Author(s):  
Kirolos D. Kelada ◽  
Daniel Tusé ◽  
Yuri Gleba ◽  
Karen A. McDonald ◽  
Somen Nandi
Keyword(s):  
Economic Analysis ◽  
Process Simulation ◽  
Large Scale ◽  
Recombinant Expression ◽  
Molecular Farming ◽  
Consumer Preference ◽  
Production Method ◽  
Long Term Effects ◽  
Adverse Health Effects ◽  
Sweet Proteins

There are currently worldwide efforts to reduce sugar intake due to the various adverse health effects linked with the overconsumption of sugars. Artificial sweeteners have been used as an alternative to nutritive sugars in numerous applications; however, their long-term effects on human health remain controversial. This led to a shift in consumer preference towards non-caloric sweeteners from natural sources. Thaumatins are a class of intensely sweet proteins found in arils of the fruits of the West-African plant Thaumatococcus daniellii. Thaumatins’ current production method through aqueous extraction from this plant and uncertainty of the harvest from tropical rainforests limits its supply while the demand is increasing. Despite successful recombinant expression of the protein in several organisms, no large-scale bioproduction facilities exist. We present preliminary process design, process simulation, and economic analysis for a large-scale (50 metric tons/year) production of a thaumatin II variant using several different molecular farming platforms.

scholarly journals EXPRESS: COVID-19 AND STROKE – UNDERSTANDING THE RELATIONSHIP AND ADAPTING SERVICES. A GLOBAL WORLD STROKE ORGANISATION PERSPECTIVE

2021 ◽  
pp. 174749302110064
Author(s):  
Hugh S Markus ◽  
Sheila Cristina Ouriques Martins
Keyword(s):  
Large Scale ◽  
Stroke Care ◽  
Long Term Effects ◽  
Vessel Occlusion ◽  
Stroke Incidence ◽  
Stroke Research ◽  
Incidence And Mortality ◽  
Research Initiatives ◽  
Global World

A year ago the World Stroke Organisation (WSO) highlighted the enormous global impact of the COVID-19 pandemic on stroke care. In this review we consider a year later where we are now, what the future holds, and what the long term effects of the pandemic will be on stroke. Stroke occurs in about 1.4% of patients hospitalised with COVID-19 infection, who show an excess of large vessel occlusion and increased mortality. Despite this association, stroke presentations fell dramatically during the pandemic, although emerging data suggests that total stroke mortality may have risen with increased stroke deaths at home and in care homes. Strategies and guidelines have been developed to adapt stroke services worldwide, and protect healthcare workers. Adaptations include increasing use of telemedicine for all aspects of stroke care. The pandemic is exacerbating already marked global inequalities in stroke incidence and mortality. Lastly the pandemic has had a major impact on stroke research and funding, although it has also emphasised the importnace of large scale collaborative research initiatives.

Ecological processes maintaining differential tree species distributions in an Australian subtropical rain forest: implications for models of species coexistence

2000 ◽  
Vol 16 (3) ◽  
pp. 387-415 ◽  
Author(s):  
Igor Debski ◽  
David F. R. P. Burslem ◽  
David Lamb
Keyword(s):  
Species Composition ◽  
Tree Species ◽  
Rain Forest ◽  
Large Scale ◽  
Species Coexistence ◽  
Common Species ◽  
Size Class ◽  
Differential Mortality ◽  
Mixed Composition ◽  
Large Scale Disturbance

All stems ≥ 1 cm dbh were measured, tagged, mapped and identified on a 1-ha plot of rain forest at Gambubal State Forest, south-east Queensland, Australia. The spatial patterns and size class distributions of 11 common tree species on the plot were assessed to search for mechanisms determining their distribution and abundance. The forest was species-poor in comparison to many lowland tropical forests and the common species are therefore present at relatively high densities. Despite this, only limited evidence was found for the operation of density-dependent processes at Gambubal. Daphnandra micrantha saplings were clumped towards randomly spaced adults, indicating a shift of distribution over time caused by differential mortality of saplings in these adult associated clumps. Ordination of the species composition in 25-m × 25-m subplots revealed vegetation gradients at that scale, which corresponded to slope across the plot. Adult basal area was dominated by a few large individuals of Sloanea woollsii but the comparative size class distributions and replacement probabilities of the 11 common species suggest that the forest will undergo a transition to a more mixed composition if current conditions persist. The current cohort of large S. woollsii individuals probably established after a large-scale disturbance event and the forest has not attained an equilibrium species composition.

Water Conflicts: The Case of the Nile River and the Grand Ethiopian Renaissance Dam

2020 ◽  
Vol 65 (2) ◽  
pp. 179-193
Author(s):  
Cătălin Badea
Keyword(s):  
Water Resources ◽  
Large Scale ◽  
Life Form ◽  
Complex Problem ◽  
Modern Technology ◽  
Nile River ◽  
Water Conflict ◽  
Water Conflicts ◽  
Potential Conflict ◽  
State Of Water

"The most crucial element of every life form on our planet, water has always been a source of potential animosity between clans, tribes and even states. With the advent of modern technology we have devoted less and less of our attention to this all-needed resource, but pollution, large-scale industrialization and agriculture, the population boom of the last centuries and crucially the climate calamity that it threatens to unleash, forces us to reconsider the key role played by water in the delicate and fragile ecosystem of our planet. This article takes a look at how water is, and will increasingly be, a source of contention and even conflicts between states, as climate changes and increasingly larger populations will be forced to fight over more and more depleted resources. With a focus on the case of the Nile river and the potential conflict over its water resources between Egypt and Ethiopia, this article examines how the mainstream state of water conflict thinking fails to explain the case of the Nile River Basis and the newly built Grand Ethiopian Renaissance Dam (GERD) and why the alternative ideas that are based on the notions of cooperation and justice might ultimately provide a better way of understanding the complex problem of the delicate management and use of water resources. Keywords: Water conflicts, Egypt, Ethiopia, GERD, The Nile"

Nucleic acids in prion preparations: unspecific background or essential component?

1994 ◽  
Vol 343 (1306) ◽  
pp. 425-430 ◽  
Keyword(s):  
Nucleic Acid ◽  
Nucleic Acids ◽  
Large Scale ◽  
Size Range ◽  
Complete Recovery ◽  
Tissue Homogenate ◽  
Purification Step ◽  
Prolonged Incubation ◽  
Purification Scheme ◽  
Nucleic Acid Analysis

As recently published (Kellings et al. J. gen Vir. 73, 1025-1029 (1992)), the analysis of purified scrapie prions by return refocusing gel electrophoresis revealed remaining nucleic acids in the size range up to 1100 nucleotides. The results defined the possible characteristics of a hypothetical scrapie-specific nucleic acid. If homogeneous in size, such a molecule would be less than 80 nucleotides in length at a particle-toinfectivity ratio (p: i) near unity; if heterogeneous, scrapie-specific nucleic acids would have to include molecules smaller than 240 nucleotides. To decrease the amount of nucleic acids, several modifications of the PrP Sc purification scheme were introduced. Instead of sucrose gradient, ultrafiltration was applied as a purification step and nucleic acids were degraded by BenzonasetM after ultrafiltration, but significant reduction of the p: i ratio could not be achieved. To prevent trapping of nucleic acids in prion rods, nuclease (Benzonase™ ) was added into the tissue homogenate and incubated at 37°C, overnight. The Benzonase treatment revealed no loss of infectivity, but the whole procedure of nucleic acid analysis did not lead to a reduction of the p :i ratio. In another approach the number of nucleic acid degradations steps was reduced to essentially two steps: Zn 2+ hydrolysis and Benzonase digestion. Higher Zn 2+ concentrations and prolonged incubation times resulted in a more efficient nucleic acid degradation. The bioassays yielded complete recovery of infectivity. Large-scale preparations for determining the p: i ratio are still underway

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